Tear strip creation on zipper flanges

Abstract

The disclosure pertains to various embodiments of zippers with a tear flange for use in a reclosable flexible package or bag. A line of weakness can be introduced into the tear flange by application of a peel seal polymer resin or of a foaming agent. The disclosure includes further embodiments wherein lines of weakness are introduced into the flange of zippers in reclosable packages or bags.

What is claimed is: 
     
       1. A zipper for a reclosable package, including:
 a first zipper profile segment with a first interlocking element and a first flange; 
 a second zipper profile segment with a second interlocking element and a second flange; 
 the first flange including a first line of weakness of controlled density reduction formed in response to co-extrusion of a foaming agent in the first flange, wherein the first line of weakness permits tearing of the first flange; and 
 wherein the second flange includes a second line of weakness of controlled density reduction formed in response to co-extrusion of a foaming agent in the second flange, wherein the second line of weakness permits tearing of the second flange. 
 
     
     
       2. The zipper of  claim 1  wherein the first and second lines of weakness are formed parallel to the first and second interlocking elements. 
     
     
       3. The zipper of  claim 1  wherein the foaming agent causes a twenty percent density reduction in the first line of weakness and the second line of weakness with respect to remaining portions of the first and second flanges. 
     
     
       4. The zipper of  claim 1  wherein the first and second zipper profile segments are both formed from a single self-mating zipper. 
     
     
       5. The zipper of  claim 1  wherein the first and second zipper profile segments are separate from each other.